The Linux version is only available as a rpm package for openSUSE 12.3 and 13.1 right now, just do a “zypper in dolphinviewer3-beta” after adding the repository (instructions are on the download page) to try it out.

Update: the download link for a Linux version of the Dolphin Viewer 3 BETA is here. Of course openSUSE users can simply install it with zypper or from YaST, if the repository has been added.